A known technology predicts a position where an own vehicle and an object, which is measured by sensors, such as a camera and/or a radar, around the own vehicle would collide with each other, thus performing drive assist of the own vehicle. The drive assist is to avoid a collision between the own vehicle and the object or mitigate damage due to a collision. Such a technology is disclosed in, for example, patent document 1.
A drive assist apparatus, which performs such drive assist, for example calculates a time to collision (TTC) with an object based on a relative speed of the object relative to a vehicle and a distance between the vehicle and the object. The TTC represents a time until which the vehicle would collide with the object. Then, the drive assist apparatus performs the drive assist when the TTC, which has been decreasing as the vehicle has been approaching the object, reaches one of activation thresholds previously determined for the respective types of drive assist including automatic braking and automatic steering.